Improvement in steam-engine valves



IA. W. FOX.

Improvement in Steam-Engine Vaves.

Patented oct. 22,1872.

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UNITED STATES PATENT QEEJICEo AARON W. FOX, OF UNION, NEV YORK.

IMPROVEMENT IN STEAM-ENGlNE VALVES.

Specification forming part. of Letters Patent No. 132,360, dated October22, 1872 antedatcd October 19, 137-2.

To alt whom t may concern:

Be it known that I, AARON W. FOX, of Union, in the county of Broome andState of New York,` have invented certain Improvements in Steam-Engines,of which the following is a specification:

The first part of my invention relates to the arrangement of aneccentric rod, the back end of which is free to swing in a curved slotin a vibrating arm, one end of which arm is pivoted to the bed-plate,and the other end is attached to the valve-rod. The governor is attachedto the eccentric rod, to regulate its position Vin the curved slot, andthese parts are so arranged with reference to the length of theeccentric rod, length and position ofthe vibrating arm; and lap of thevalve, that steam is admitted to the cylinder at the proper momentwithout any regard to the distance the valve travels; and by thisarrangement I obtain a variable expansion engine, worked by thegovernor, and use only a single valve. The second part of my inventionconsists in the employment of a ring at the end of a cylindrical valve,where 'the steam is admitted to the interior thereof,

to prevent steam leaking through, and thereby keep the valve balanced.

In the accompanying drawing, Figure 1 is a side elevation of an engineembodying the rst part of my invention; Fig. 2 is a verticallongitudinal section of the cylinder, ports, and valve; Fig. 3 is avertical transverse section ofthe cylinder, bed-plate, and valve, at theline s s drawn across Fig. l and Fig. 4 is a section, on a larger scale,of the valve and its surroundings, the same as Fig. 3, to show moreclearly the ring, its form and position, which is the second part of myinvention.

A is the bed-plate of the engine, which bed-plate does not differ inform from those in common use, nor is it necessary to make anyparticular form of bed-plate in order to use my invention. B is thecylinder, a section of which is clearly shown in Figs. 2 and 3, theinduction and eduction ports, also a cylindrical opening for the valvec, being all made together in a single casting. The cylinder is bored,and piston fitted in the ordinary manner. The cylindrical opening acrossthe top is bored out true and smooth, and the valve cis turned andfitted therein; the valve being cylindrical externally, is made hollow,

with a concave or D extending nearly its whole length 011 the under sideto exhaust steam. The valve has also a port or narrow opening in eachside, from the interior to the outside, Fig. 2, which, as the valverolls back and forth, are brought in connection with the ports aca: toadmit steam to the cylinder. The valve has a stem on'one end, Figs. 3and 4, on the outer end of which is tted a short arm, a, Figs. l and 3,by means of which motion is given to the valve. To the lower end of thearm a is attached one end of the valve-rod d, Fig. 1, the other endbeing attached to the top of the vibrating arm n, the lower end of thearm u turning on a stud in the bed-plate at its base. The vibrating armis provided with a curved slot through which a pin passes, connectingthe arm n to the rear end of the eccentric rod m. rlhe eccentric rod mtakes motion from an eccentric on the engineshaft in the usual manner.The governor, Fig. l, stands on the bed-plate A, and by means of avertical rod gives motion to a horizontal lever, e, at tached bya studin its center to the bed-plate, while the rear end has a short link, i',extending upward, and is connected to the eccentric rod near the endwhere it is connectedA to the arm n. The parts of the engine notparticularly described are made, or may be made, without change from anyofthe forms of such parts in common use.

The engine being completed and set up, I will describe its operation: Ifit is in the position shown in Fig. l-that is, on its center 7 with thecrank horizontal and extending outward, the valve will be in theposition to Commence admitting steam to the end of the cylinder towardthe crank, as seen in Fig. 2, and the lap7 of the valve will be all onthe other side. The short arm a on the valvestem andthe vertical slottedarm n are both perpendicular when the valve laps equally on each side ofthe ports, but as shown, they incline sufficiently to place the valve inthe p0- sition described. The eccentric being properly set, its largeside is nearly upward, or above the engine-shaft, thus elevating thatend of the eccentric rod, and it will be now seen that nif the arm n,and eccentric rod m, are ofthe proper length to correspond with therequired lap of the valve, the eccentric rod will be as the radius ofthe curved slot in the arm n, and the end of the eccentric rod may bemoved from one end of the slot to the other without changing theposition of the valve. The engine being turned half a revolution, in thedirection ot the arrow above the eccentric, the crank is on the oppositecenter, the large side of the eccentric is nearly under the shaft, thearm n inclines toward it, and the eccentric rod and arm are in the sameposition with respect to each other as in the position first described,and the valve is in position to commence admitting steam to the back endof the cylinder. The governor, by means of the lever e, and link o",regulates the position of the end of eccentric rod in the curved slot,and this controls the travel of the valve, and the amount of steamadmitted to the cylinder according to the motion of the engine, and thevalve is always in position to admit steam at the proper time, withoutregardvto the amount of steam or power required. The openings in thecylinder easting'oecupied vby the valve, and the exhaust-steam passage yunder it, are covered at their ends by plates or covers 7L h, Figs. l,3, and 4. One has a single hole in it for the valve-stem to passthrough, and the other plate has a hole at the center ofthe valve toattach a pipe through which steam is supplied to the interior of thevalve, and directly under it is another pipe screwed into the plate hconnecting with the steam-passage y, through which passes offexhaust-steam. The open end of the valve shouldnt steam-tight againstthe plate in which the pipes are screwed, but

if by neglect or wear the valve is not kept steam-tight against theplate, steam will pass through and above the valve, thus destroying itsbalance. To obviate this difculty, the inside of the valve is turnedsmooth a short distance at the open end, Fig. 4, and the hole in theplate h, where the supply-pipe is attached, is also turned to correspondwith the end of the valve. Both the openings are largest at the joint,decreasing in diameter as they recede from it. A ring, fv, Figs. 3 and4, is turned to it in the angle so formed, and cover the jointsteam-tight, and prevent leakage if the end of the valve is not keptclose to the plate hf.

I do not claim any form of bedplate, piston, cross-head, or governor',nor do I claim broadly a rolling valve; but

What I do claim, and desire to secure by Letters Patent, is-

l. The arrangement of the eccentric rod m, vertical vibrating arml11'va-lve-rod d, and rock-valve c, together with the link 1', andhorizontal lever e, attached to and operated by a governor, constructedsubstantially in the manner herein set forth.

2. In combination, the hollow rocking valvev c, and the ring o, whenthese parts are constructed in the manner, and operating substantially,as herein described.

A. WV. FOX.

Witnesses:

JOHN M. SKILLMAN, ROBERT T. Mnnsnnnnn.

